This invention relates to apparatus for recording and reading data on a magnetic media and more particularly on a magnetic disk. More particularly, the invention relates to apparatus for initializing counting mechanism which keeps track of the particular magnetic track on which a magnetic head is located when the head moves across a prerecorded reference track on the disk.
Heretofore, it has been the practice to count the particular tracks on a magnetic disk over which a magnetic head positions using a counter which counts for each track traversed by the magnetic head. When such a system is used in connection with rigid disks, relatively no difficulty has been had in locating the inner tracks; however, when a thin flexible disk is used in lieu of the relatively rigid magnetic disk, the changes in dimension of the thin disk with time, temperature and wear have caused a lack of correspondence between the content of the counter and the position of the magnetic head.